Traveling grate incinerator for city refuse and the like



Sept. 13, 1949. T. FERRO ET AL TRAVELING GRATE INCINERATOR FOR CITY REFUSE AND THE LIKE Filed April 22. 1944 6 Sheets-Sheet 1 MATEO m. MAHOV. Z. i. M

Sept. 13, 1949. T. FERRO ET AL 2,481,504 TRAVELING GRATE INCINERATOR FOR CITY REFUSE AND THE LIKE Filed April 22. 1944 6 Sheets-Sheet 2 3 //V l/E/V 727/4 5 THOMAS FERRO MATEO M. MAN'oV 5 MM..7Jwm rd Sept. 1-3, 1949. T. FERRO ET AL TRAVELING GRATE INCINERATOR FOR CITY REFUSE AND THE LIKE Filed April 22. 1944 6 Sheets-Sheet 3 n N 131 "7" W I K V '1 i Q R; i RMHMTM; Q: n :1 i E HUME 33 :12; 31".": 91:3 /Vl E/V7Z7E5.

THOMAS FERR'O MATEO N- MAHov AJ -S.W

Sept. 13, 1949. FERRO ET 2,481,504

TRAVELING. GRATE INCINE OR FOR CITY REFUSE AND THE LIKE Filed April 22. 1944 6 Sheets-Sheet 4 Sept. 13, 1949. T. FERRO ET AL 2,431,504

TRAVELING GRATE INCINERATOR FOR CITY REFUSE AND THE LIKE Filed April 22. 1944 6 Sheets-Sheet 5 Sept. 13, 1949. T. FERRO ET AL 2,481,504

TRAVELING GRATE INCINERATOR FOR CITY REFUSE AND THE LIKE 6 Sheets-Sheet 6 Filed April 22. 1944 MATEO M. MANOV. 6 6/11. 2 7

Patented Sept. 13, 1949 2,481,504 TRAVELING GRATE INQINEBATQR oa CITY REFUSE AND 'rr E Linn Thomas Ferro and Mateo M. Manov, Piedmont, Calif., assignors to (Bakland 'Scave'nge'r"o., Oakland, Calif., a corporation of California Application April 22, 1944, Serial 1 I o.: 3 2,23 i

This invention relates to garbage incinerators and particularly to a traveling grate type of furnace, as distinguished from the usual floor furnace type, rotary kiln type, etc., and which has demonstrated itself by actual full-size operation to be capable of large capacity and high eiiiciency.

Among the objects of the present invention is the provision for as nearly complete combustion as is possible in apparatus of this character.

The smoke nuisance from most garbage and refuse-incinerating plants is a constant source of complaint on the part of the affected public. Much effort has been expended in seeking to alleviate or lessen thisidiflficulty. The present invention has, in practice on a large scale burning sixteen tons per hour average, demonstrated the ability to effect complete burning of the usual run of city garbage, kitchen refuse and community waste with an almost'total absence of smoke.

This desirable result is attributed, in large measure, to the arrangement of a series of traveling grates in echelon formation andmeans for distributing air for combustion through the full length of the unit, and at the same time providing space and time for the generated gases to expand periodically in their course of travel with consequent reduced rate in velocity of travel to allow the unccmbusted solids, carried in suspension, to settle and become redeposited on the grates for further incinerating action.

Other objects and advantages will appear from a description of theapparatus.

Having reference to the accompanying drawmgs:

Fig. l is a longitudinal, vertical schematic section through the furnace and the center of the chain grates.

Fig. 2 is a side elevation of the incinerator, the supporting structure and certain non-essential details being omitted.

Fig. 3 is a plan View, in partial section, on top of grates, with top of furnace removed.

Fig. 4 is a typical cross section on an enlarged scale through the furnace at points 4 4 in Fig. 1 of the drawings.

Fig. 5 is a cross section on line A-A of Fig. 3.

Fig. 6 is a cross section on line B B of Fig. 3.

Fig. '7 is a detail elevation of the spreaderplate for distributing the entering material evenly over the initial grate:

Fig. 8 is a plan view of a blank for the spreaderplate.

Fig. 9 is a detailof the lump-breaker assembly.

Fig. 10 is an end view of the lump-breaker assembly with the side walls of the furnace not showing.

Fig. 11 is a detail in vertical section of the adjacent ends of -two grate members, showing arrangement of draftbaffle.

'7 Claims. (Cl. 110-?) The furnace A in Fig. Iis an elongated, massive structure suitable construction, with" reinforced fireproof walls and'c'eiling, and adapted to house a series of "horizontally disposed, stepped, endless traveling grates 31 4 and 5, on which the garbage is progressively advanced the furnace from it s delivery onto the first c f said gratesfuntil it's' final discharge as ash and clinker frornthe-last grate 5. y

These grates are of conventional design, but are arranged" in "stepped or echelon formation, witheach gratedeliverifigfitsload of refuse onto asucces'sive grate; the grate 5 being adjacent to the source of heat provided by th'oilf or'gas burners E5 The grates fall travel'at uniform speed and are driven ilfliilniso'niby' any suitable co venti onal 'meaiis from any 'appropriatesource of power, not believed necessary to be shown in every detail b'utiillustriitejd"schematically -in Figs. & ,7

Aspecial characteristic of this furnace is that each grate traverses an individual section or combustion chamber of the "furnace" interior, which sections or chambers are correspondingly stepped'and collectively constitute a continuous combustion space.

In an operating unit embodying this invention, the overall length I and width bf the furnace interiorareaetermisa by the quantity of garbage to be incinerated per unit gof tim e and by the moisture c'ontenttof the garlbagelin itsiinitial state as delivered on th grate. A "satisfactory result may'lbe'ob't'ained by allowing" from twenty to twenty-five minutes time 'to' burnj one cubic foot" of garbage 'having' 'ah 1oistu;re content of alooutYfiW b by weight, and a speedtof from two to fourfe et per minute 'at the chaih grates. The preferable number-jot 'chain gratesshould not be less than three and the prefe rablelength of each grate should fiottbemoif'e than twenty f our feet. The preferable of the grates should not'be less naaijaer fe'etinor more than six feet. The cross s'ct'iofialar eaabove each time should be proportional to the votumeof smoke and water vapor lproduced'at each "rate and the velocity of the combinedvolurn of smoke andfvapor should not exed 'TQD' PI through the ;hottest sectionViifthe gratefincreasing to not over 1300 F. PIM. through his coolest ct on.

In a unit recently to I ructed and nowinactual operationthe o v'eia le'rif'gth of the fl fna'ce interi'or'is "approximately eighty-four feet. The width of the grates, corresponding .to the approximate 'width of the furhacechamber, is,appi'oximately six feet. "The X gt'hsof the ind grates vary "slightly {but average approx twefity ge T temper tur in th swim varies w approximately 1400 Fahrenheit to lfifipfliflahre'n heit adjacent to the burners 6 to approximately 600 Fahrenheit to 700 Fahrenheit in chamber adjacentto the outlet 1 for the gases into a stack 8.- Eachof ,sa'ids'ections of the furnace chamber comprises, essentially, two parts of different cross-section; a part 9 of smaller cross section and a part II] of larger cross-section. The

portions I0 are each approximate to the delivery.

end of each of the traveling grates 2, 3, 4 and 5' and extend over approximately one-third of the length of the succeeding grates 3, ,4 and .5, so that For the grate 5 the air is supplied by the air blower through, air trench 4| to the bottom of theside walls. of the furnace A andinto a manifold 33 and thence through air ports 42 on the inside face of these walls to points as noted on Figs. 1-3 fortfie lfgtes 2, 3 and 4. The blower can be of anyconventional design, having a conventional flow control, indicated at 44, and a-capacity-of not'less than '760 C. F. M. at about /1" each portion l0 constitutes, in practice, an expansion and precipitation chambenwhereby the velocity of travel of the gases through the furnace from the burner end of the furnace towards. Q

The dimensions of the sections 9 and ID of the furnace space vary progressively from the burner end of the furnace, adjacent to the grate 5, to the opposite end ofthefurnace.

Based on the foregoing data,the operative unit has the fOllOWing critical dimensions:

Chamber 9 over grate 5 is approximately 17'X6'x4;-j

Chamber [0, which encloses the receiving end of grate 5, is approximately 8' x 6' x 7';

Chamber 9 over grate 4 is approximately 14 X 6'- x 5'; r k

Chamber l0 over the receiving end of grate 4 is approximately 6' x 6' x 8'; r

Chamber 9 over grate 3 is approximately 14 x 6' x 5' 3";

Chamber in over the receiving end of grate 3 is approximately 6' x 6' x 9'; j

Chamber l9 over the initial grate 2 is approximately 6' x 6' x 6'; and

Chamber I0 over the receiving end of grate 2;

is approximately 7 x 6" x 6' x 8.

These figures, of course, would vary in units of different sizes and capacities The present apparatus has a demonstrated capacity for burning approximately sixteen tons of miscellaneous garbage and refuse per hour.

An apparatus of this character must be designed on the assumption that it is handlin the} worst garbage with a large assortment of kitchen refuse, with very considerable Water content and normally producing, when incinerated, a tremendous volume of smoke as compared with dry garbage. I

Normally, the apparatus herein described is operated so that complete combustion is effected in from twenty to twenty-five minutes, more or less, figuring the time that it takes the material to be burned to travel from the point where it is first delivered onto grate] until it is discharged as ash or clinker from grate 5. Only theproducts of evaporation and the lighter colorless gases issue from the stack. 7 r

The combustion of the gases in their progress through the furnace is aided andaccelerated by the admission of regulated quantities of air through both sides of the furnace and at points just below the top of the traveling grates 2, 3 and 4 through air ports H which are controlled by slide gates 12.

S..P.. per tonof; garbage to be burned per hour. Thus the air. for :combustion is distributed in properregulated quantity and uniformly through the full length of the unit, whereby a very satisfactorydegree of combustion is obtained. These air ports are disposed, preferably three on each side to each" grate except the first or grate 2- in the initial feed chamber where itmay require. only one or two. The admissionof air through ports I! is manually controlled withrelatiozi to; the burner draft, so that the. gases travel through the furnace at a speed of approximatelyseven hundred feet to eighteen hundred feet per minute, as described above:-

The smoke givenfoffof grate 5 nearest the burner is heavier and denser than at any other place in the furnace, progressively decreasing in density as-the stack-end ofthe furnace is ap-} proached; the nea'rerthefstack the moresteam arises, resulting in' the final and complete dehydration of the material on the grates by the time is it entered the zones-of greate t heat whereit fully combusted or reduced to ash and clinker.

Referring to Figs. 1 and 11, it will be noted that at the lapping end of grates 2 and}, 3 and 4, and 4 and 5, there is a draft stop or baflieplate 45 to prevent the flowing gases from carrying the garbage outside the combustion chamber and beneath the upper grate. The draft stop or baffle I is a steel plate extending the full width of the furnace. The topedge ofthe plate is hinged or otherwise'suspended, as at 46, from the return rails of the traveling grates and the bottom edge is left free and slightly above the top of its lower grate, the plate resting: by gravity on the shelf member 41.

An important feature of this invention lies in the means for equally distributing the incoming garbage to the traveling incinerator floors pro vided by the grates.

The garbage "or refuse for the incinerator is delivered from; the usual conveyer and sorting means, illustrated in Letters Patent No. 2,257,567,

of September 30, 1941, but not necessary to be shown here, through 'a'feed pipe or chute 13 Inasmuch as this material comes into the furnace through chute 3 at varyingvelocities and in varyingquantities, due to-the changing variety 'of the garbage itself, it is necessary, in order to prevent the entering garbage from piling up at any particular point on;the limited area of the receiving grate 2, that some suitable means be devised by which a proper distribution and level ing off; of the garbage on'the grate -couldbe effected without an operator having to attempt such distribution bymeans of a rake o'ryotherwise. To that end, we have devised a special form of distributing. plate M, of peculiar design in cross section'but so disposed, wtih relation to the Ol1t let from the chute 13,. that the garbage. received upon theplate is divided, diverted and spread in such fashion that an even' distribution of the garbage on the grate is effected, this even dis-,5

tribution thereafter'being maintained uniform throughout the travel of the garbage through the furnace. Plate I4 is Of'sheet,metal which before assume being bent, is substantially in the form of a se ment of a circle with the two sides or lateral edges of the segment subtending an angle of approximately 90 (see Fig. 8). The plate is folded or bent into proper shape along the radial median line I5 into approximately two equal sloping sections a-a, disposed at approximately 90 from each other. The plate thus shaped is suitably pivoted at the apex I6 to a fixed part of the furnace immediately below the outlet of the chute I3 and centrally thereof and with the lateral edges I'I resting freely against the back wall I8 of a garbage-receiving compartment I9.

In order to shift the position of this distributing plate conveniently from a point exteriorly of the compartment I9 any suitable means may be provided. As here shown, a slide rod 29 extends through the side wall of compartment !9, into the compartment, and is loosely attached to the plate I4, as at 2 I, so that the plate may be moved in an are about its pivot I6 into any desired position from normal, represented for instance in Fig. 6 by dotted lines 22. By this means, if garbage is coming in more to one side of the chute I3 than to the other, the plate can be moved about its pivot I6 to vary the pitch and position of one or the other of .the surfaces a. In such a case the garbage slides along that surface which has the greater inclination. Observation of the behavior of the incoming garbage may be observed from time to time through the door iii in compartment I9.

With the plate in normal position so that the pitch of each side a is aproximately the same, the garbage slides over both surfaces, as well as down the middle, and by appropriate manipulation of the slide rod the leveling off of the garbage one the grate is accomplished.

The receiving compartment is partially cut off from the interior of the furnace proper by the baflie wall 23 which has its bottom edge suitably positioned above the grate and the incoming garbage to allow the latter freely to pass and at the same time allow very little of the heat or gases of the furnace proper to escape into the receiving compartment. The outlet for the steam, gases and remaining smoke from the furnace interior is through the port 1 into a precipitation tank 24, of conventional design, where the gases and any solid particles in suspension are subjected to a centrifugal action and to water sprays resulting in a knocking down and deposit in the tank of all-such products not in gaseous form. The remaining scrubbed gasses pass up the stack 3 so that when they issue from the stack they are almost invisible to the naked eye and, besides, are harmless and unobnoxious.

Another important f'eau're of this invention is the provision of a lump-breaker, indicated at 25 (Fig. 1) and shown in detail in .Figs. 39 and 10. Such a device is made necessary due to the-fact that there is often mixed with the refuse mate rial undergoing incineration "lumpy articles like books, tightly bound bundles, clinker, and the like, which are not broken up by merely tumbling from one grate to the other but require more forceful means to disintegrate them'so that the 'uncombusted portions may be thoroughly consumed.

To this end, at some -suitabl'e ipoint in the course of travel, preferablyover grate 5 where the he'a'tii's greatest, we dispose saidelump-breaker which, in practice, consists of a crosswise extending roller, comprising a hollow axle 21 with a series of staggered arms 2 13, whose orbits of movement are slightly above and out of contact with the top night or floor portion of the grate 5 immediately beneath. The axle 0f the breaker is preferably of heavy metal eight-inch pipe, the 5 length of which is 'sufficient not only to extend over the full'width of the grate but to project through the walls of the furnace .A and to be, journaled, driven and water-cooled from'outside the furnace preferably as follows: 0 Each end of the pipe outside the furnace walls has welded to it an end plate 29, with a central opening 38. is a flange 3 i, which, in turn, is welded to a shaft or pintle member 32, having a central bore 33 in continuation with the opening in plate 2-9, through which a cooling fluid may be admitted to pipe 2? from a suitable source of supply through a metallic hose 34 and a pipe section 35. The latter is made to have a snug running watertight fit inside shaft 32 by means of a packing gland 35. i

The breaker arms 28 consist of pipe sections which are screwed in or otherwise attached at intervals to pipe 21 in staggered relation and capped at the ends, as shown, permitting the fluid for cooling purposes to enter the arms fromthe axle pipe 21. This breaker is operated to rotate in a reverse direction to the travel of the underneath top flight or floor portion of the grate.

As seen in Figs. '2 and 3, the drive for this; lump-breaker may be provided by an extension 3'! from the drive end of the chain grate '5', or'in any other suitable manner.

We claim:

1. An incinerator for city refuse and the'lilre comprising, in combination, a furnace enclosing a continuous horizontally disposed series of chambers, the tops of said chambers being arranged in stepped formation, 'a series of correspondingly arranged, stepped traveling grates in said chambers whereby refuse received upon the topmost of the grates is delivered successively.

to the grates below, means to feed refuse into said furnace and onto the topmostgrate, heating means at the lowermost of said chambers, the

chamber spaces in the furnace over each grate being of successively decreasing cross sections,

the greater of said cross sections being at the feed end of the respective grate, whereby the. heat and the products of combustion carried by the heated gases are allowed gradually to expand as the said gases progress abovesaid traveling grates through the furnace from one cha n her to the other, and an outlet for said ,gases arranged above the topmost grate.

2. In an incinerator for city refuse and the like comprising, in combination, an elongated furnace having a horizontally connected series of combustion chambers, the tops of said chambers being arranged in stepped formation, correspondingly arranged, stepped traveling grates, whereby the refuse relivered onto the topmost initial grate is delivered successively-to the grates below, means to feed refuse into said furnace and onto the topmost grate, and means at the lowermost grate for heating the .furnace toeffect incineration, the chamber spaces overeachigrate being of successively decreasingcross-section,

the greater of said cross-sections being cat the feed end of the grate, the smallest cross section being located adjacent to the heating means :and the'largest cross section located adjacent to-,; t1 1e refuse receiving end of said furnace, whereby the products of combustion are permitted to expand Bolted and welded to each plate 29.

in their travel through the-furnace, said furnace-having ages and smoke outlet from the top most initial chamber, said latter chamber di vided into two compartments, one of'which is a refuse-receiving compartment with means in said compartment for distributing the incoming refuse evenly overthe grate. a

'3." An incinerator for city refuse and the like, comprising, in combination, a furnace enclosing a continuous horizontally disposed series of chambers the tops ofsaid chambers arranged vertically in echelon, a series of correspondingly arranged stepped traveling grates in said chambers whereby refuse-received upon thetopmost of said grates is 1 delivered successively to; the grates below, means to feed refuse into said furnace and onto the to pmost grate, said grates forming with the tops and side walls of corresponding chamber an operating space of successively decreasing cross section from the topmost grate to the lowermost of said grates, heating means applicable at the lowest of, said chambers and adapted to diffuse its heat successively-over the grates above, means for admitting air'beneath and at the sides of the lowermost of said seriesof grates, air distributing means disposed along the length of the furnace at the sides of the other grates, and means for regulating said last named air distributing means. 4. An incinerator for city refuse and the like, comprising, in combination, a furnace enclosing a .continuous horizontally disposed series of chambers the tops of said chambers being arranged vertically in echelon, a series of corre-' spondingly arranged, stepped, endless, traveling grates in said chambers, saidgrates movable longitudinally within said chambers whereby refusereceived upon the topmost ofsaidgrates-is de-. 'livered successively to the grates below, meansto feed refuse into said furnace and onto the topmost grate, said grates forming with the tops and side walls of corresponding chambers oper-v ating space of successively decreasing cross sec tion from the topmost grate to the lowest said grates, the largest cross section being located above the topmost grate and the smallest cross section above the lowest grate, heating means ap- V plicable at the lowest of said chambers andadapted to diffuse its heat successively over the grates above, air distributing means for combus tion disposed along the length of the furnace at successive grate levels, distributing means located adjacent to the refuse receivingend of said fur? nace whereby the refuse is uniformly distributed,

on said grates, and an exit for the gases of com bustion adjacent to the point of entry of the refuse into the furnace.

5. An incinerator for city refuse and the like, comprising, in combination, a furnace enclosing a continuous horizontally disposed series of chambers the tops of said chambers being ar ranged vertically in echelon, a series of correspondingly arranged, stepped, traveling grates,

in said chambers whereby refuse received upon. e

the topmost of said grates is delivered successively to the grates below, means to feed refuse into said furnace and onto the topmost grate,

said grates form n with thetops and side walls of corresponding chambers operating space of successively decreasing cross section from the topmost grate to the lower-most grate, thelargest cross section being located above the topmst grate and the smallest crosssection above the lowest 'grate'fheating means applicable at the lowest of said chambers and adapted to diffuse its heat successively over the grates above, means for admitting air beneath and at the sides of the lowermost of saidseries of grates, distributing means located adjacent to the refuse receiving end of said furnace whereby the refuse is uniformly distributed on said grates, air distributing means disposed along the length of the furnacean adjacent grate, said grates forming'with the topsand sidewalls of corresponding chambers operating space of successively decreasing cross section from the topmost grate to the lowermost V grate, the largest cross section being located above the topmost grate and the smallest cross section above the lowest grate, means to feed refuse into said furnace and 'onto the topmost grate, and heating means located adjacent to said lowermost grate. I r

7. An incinerator for city refuse and the like, comprising in combination a furnace enclosing a continuous horizontally disposed series of chambers, the tops of said chambers being arranged in vertically echeloned formation, a series of endless traveling grates in said chambers positioned in stepped formation corresponding to the formation of the tops of the chambers whereby refuse received upon the topmost of said grates is delivered successively to the grates below, said traveling grates being arranged to form with the top,

of said chambers an operating space of successively decreasing height fromthe chamber hous-. 7

ing the topmost grate to the chamber housing the lowermost grate, means. to feed refuse into said furnace and onto thertopmost grate, heating;

means applicable atthelowest of said chambers and adapted to diffuse its heat successively over 7 the grates above, air distributing means for com-,

bustion disposed along the length of the furnace at successive grate levels, and an exit for the gases of combustion adjacent to the point of entry of thezrefuse into the furnace.

' I-IOMAS- FERRO.

MATEO M, MANOV.

REFERENCESI'VVCITYED .The following references are of record in the file of this patent: 7

UNITED STATES PATENTS Number .Name 7 7 Date 1,170,376. Wedge'n- Feb. 1, 1916 1,659,564 Duncan Feb. 21, :1928' 1,760,694 Hartley May '27, 1930 1,778,249 Drewer Oct; 14, 1930' 1,797,335 Fedeler .Mal. 24,1931- 1,918,535 Greenwalt July 18, 1933 1 2,269,273 I Krogh Jan.'6, 194

' FOREIGN PATENTS Number. Country Date France May 18, 1911 

